Cytogenetic biomonitoring in mucopolyssacharosis I, II and IV patients treated with enzyme replacement therapy

Evidence of epigenetic landscape shifts in mucopolysaccharidosis IIIB and IVA

Lysosomal storage diseases (LSDs) are a group of monogenic diseases characterized by mutations in genes coding for proteins associated with the lysosomal function. Despite the monogenic nature, LSDs patients exhibit variable and heterogeneous clinical manifestations, prompting investigations into epigenetic factors underlying this phenotypic diversity. In this study, we focused on the potential role of epigenetic mechanisms in the pathogenesis of mucopolysaccharidosis IIIB (MPS IIIB) and mucopolysaccharidosis IVA (MPS IVA). We analyzed DNA methylation (5mC) and histone modifications (H3K14 acetylation and H3K9 trimethylation) in MPS IIIB and MPS IVA patients' fibroblasts and healthy controls. The findings revealed that global DNA hypomethylation is present in cell lines for both diseases. At the same time, histone acetylation was increased in MPS IIIB and MPS IVA cells in a donor-dependent way, further indicating a shift towards relaxed open chromatin in these MPS. Finally, the constitutive heterochromatin marker, histone H3K9 trimethylation, only showed reduced clustering in MPS IIIB cells, suggesting limited alterations in heterochromatin organization. These findings collectively emphasize the significance of epigenetic mechanisms in modulating the phenotypic variations observed in LSDs. While global DNA hypomethylation could contribute to the MPS pathogenesis, the study also highlights individual-specific epigenetic responses that might contribute to phenotypic heterogeneity. Further research into the specific genes and pathways affected by these epigenetic changes could provide insights into potential therapeutic interventions for these MPS and other LSDs.

Genomic Instability in Peripheral Blood and Buccal Mucosal Cells of Marijuana Smokers: The Impact of Tobacco Smoke

BACKGROUND

The aim of this study was to evaluate cytotoxic, mutagenic and genotoxic effects on buccal mucosa and peripheral blood cells from marijuana and tobacco smokers.

METHODS

For this purpose, a total of 45 volunteers were distributed into four groups: CTRL group (control): individuals who did not smoke marijuana or tobacco (n = 11); Group M: Marijuana smokers (n = 13); Group T: Tobacco smokers (n = 13); Group M + T: Smokers of both marijuana and tobacco (n = 08).

RESULTS

Smokers of both marijuana and tobacco led an increase of micronucleated cells on buccal mucosa when compared to control group. The occurrence of karyolysis showed significant changes in this group as well. The comet assay data revealed genetic damage in peripheral blood cells for all groups of smokers.

CONCLUSION

In summary, our results showed that marijuana and /or tobacco are able to induce genetic damage and cytotoxicity in oral and peripheral blood cells.

Intravenous Enzyme Replacement Therapy in Mucopolysaccharidoses: Clinical Effectiveness and Limitations

The aim of this review is to summarize the evidence on efficacy, effectiveness and safety of intravenous enzyme replacement therapy (ERT) available for mucopolysaccharidoses (MPSs) I, II, IVA, VI and VII, gained in phase III clinical trials and in observational post-approval studies. Post-marketing data are sometimes conflicting or controversial, possibly depending on disease severity, differently involved organs, age at starting treatment, and development of anti-drug antibodies (ADAs). There is general agreement that ERT is effective in reducing urinary glycosaminoglycans and liver and spleen volume, while heart and joints outcomes are variable in different studies. Effectiveness on cardiac valves, trachea and bronchi, hearing and eyes is definitely poor, probably due to limited penetration in the specific tissues. ERT does not cross the blood-brain barrier, with the consequence that the central nervous system is not cured by intravenously injected ERT. All patients develop ADAs but their role in ERT tolerance and effectiveness has not been well defined yet. Lack of reliable biomarkers contributes to the uncertainties about effectiveness. The data obtained from affected siblings strongly indicates the need of neonatal screening for treatable MPSs. Currently, other treatments are under evaluation and will surely help improve the prognosis of MPS patients.

Genotoxicity and cytotoxicity induced by eluates from orthodontic glass ionomer cements in vitro

The aim of this study was to investigate genotoxicity and cytotoxicity of some orthodontic glass ionomer cements commercially available by means of the single cell gel (comet) assay. For this purpose, five commercial orthodontic glass ionomer cements (Vidrion C®, Meron®, Optiband®, Multicure® and Ultra Band Lok®) were tested in murine fibroblasts in vitro. For this purpose, eluates from each cement were prepared according manufactures instructions at 0, 2, 4, 8, 18, 32 and 64 days of immersion in artificial saliva at 37 °C. All orthodontic glass ionomer cements failed to induce cytotoxicity to murine fibroblasts for all periods evaluated in this study. However, Vidrion C® was able to induce genotoxicity after 64 days of exposure to eluates. Meron® also demonstrated genotoxicity as depicted by increasing DNA damage on 2nd day. Multicure® demonstrated genotoxicity on 32nd day and Ultra band Lok on 18th, 32nd days of exposure. Taken together, our results demonstrated that orthodontic cements derived from resin-modified glass ionomer composite (Multicure®) and compomer (Ultra Band Lok®) cause genetic damage in mammalian cells in vitro.